A variety of different types of agricultural tools referred to in the trade as shovels, blades, tines, and sweeps have heretofore been provided for performing agricultural operations which include crop cultivating, minimum tillage, crop cutting, and weed cutting.
A number of the present crop cultivators use a disk and knive, or a spring tine commonly called a "Danish Tooth," or a spider-like tool. These crop cultivators are frequently mounted on a shank in the slot of a tool bar clamp. Some attempts have been made to use horizontally disposed rotary disks for crop cultivating purposes. In general, those tools using a horizontally disposed rotary disk provided in the past have been an integral part of the implement or an integral part of a complete assembly and not an assembly that can be readily attached to an implement in place of other tools or used in combination with a conventional tool bar clamp or the like. In some instances the rotary disks heretofore provided have been power driven rather than freely rotatable.
The following are illustrative of the prior art patents using rotary disks:
Freeman U.S. Pat. No. 3,129,773 discloses a plurality of laterally spaced rotary disk blades mounted on a rigidly clamped axle of the vehicle in line with the axis of rotation of the disk blade.
Smith U.S. Pat. No. 4,294,181 discloses a rotary disk blade on the end of a vertical shaft that is made as an integral part of the implement frame.
Robinson U.S. Pat. No. 2,018,575 discloses the use of a rotary cutting disk mounted as an integral part of a frame for cutting the tops from onions.